Production of aromatic ketonic compounds



40' of'about 50 C.

Patented Mar. 6,1928.-

} UNITED STA FREDERICK '11. Kimnz, or BUFFALO, new

CHEMICAL co., me, or NEW YORK,

TES PATENT OFFICE.

YORK, ASSIGNQB T NATIONAL ANILINE a N.;Y., A CORPORATION or New YORK.

PBQDUCTTON or AROMATIC Knrome COMPOUNDS.

No Drawing.

known that 4.4'-diaminodiarylke tonic bodies can be prepared by heating4A-diaminodiarylmethane bodies with crys- I p tallized sodium sulfideand sulfur in a. reflux apparatus. If an linodiarylmethane body isemployed, the cor- Io responding N-substituted 4.4'diaminodiarylthioketone body is produced whereas if a4.4-diaminodiarylmethane body not substituted in' the amino groups beemploye then the corresponding 4.4J- iaminodiaryll5 ketone body isobtained. "In practicing this known process it appears advisable toemploy crystallized sodium sulfide since dry commercial sodium sulfidegives a poorer yield and a product of inferior quality.

According to the present invention, the relatively expensivecrystallized sodium sulfide is replaced by caustic alkali which offersnot only considerable economy in cost but there is produced by its usean excellent product and in superior yields.

In carrying out the present invention, the 4.4-diaminodiarylmethane bodyis heated with a'cau'stic alkali solution containing sulfur under areflux condenser until the me-.

thane body has been substantially all converted to the correspondingketone body.

Under the term ketone both the ketones and the thioketones.

The following, specific examples will further illustrate the invention,but it will be understood that the invention is not limited thereto. Theparts are by weight.

" Ewa-mple 1.To 300 parts of a fifty percent caustic soda solution, at atemperature and under good agitation,

about 105 parts of powdered sulfur are added; thev temperature rises toabout -80 85' C. When it dro' s'to about/70 C.

about 215 parts more 0 and the temperature again rises to about 80 C.and gradually falls. When the temperature has fallen to about 70 0., 200parts of tetramethyl 4.4-diaininodiphenylmethare added and the mixtureis then heated to about 120 C. The mixture is stirred at thistemperature for about 45 minutes, after which it is heated to vigorousboiling under a reflux, which boiling should beg n at a N substituted4.4'-diambody there is included sulfur are added,

Application filed April 2, 1926. Serial No. 99,406.

temperature of about 126 C. The boilin temperature increases to about127128 within the nextthr'ee hours, and it is there maintained whf l themixture is agitated for about 72 hours or until the reaction is comabout500 parts of water-are added, and the mixture is poured into about 2500parts of water kept at a temperature below 25 C.

leted. At the completion of the reaction,

and agitated for about 30 minutes, and the51.4-tetralnethyldiaminodiphenylthioketone is filtered ofi' and WashedWell with water. The

d remaining products of the reaction are mainly hydrogen sulfide, whichis removed during the vigorous boiling, and sodium thiosulfate WlllClliscarried oif in solution.

Substantially no, or very little, sodium sulfide or polysuliide ispresent in the solution at the completion of the reaction. By'thisprocedure a yield of superior quality of about ninety percent of thetheoretical ,is obtainable. V l

. Ewwmple Q.A mixture of 150 parts caustic soda, 320 parts sulfur, 150parts water and 100 parts of 4t.4-diaminodiphenylmethane, H N C H,-CH ;GH;NH are slowly heated with good agitation to about 120 C. over a periodof about 35-45 minutes and then vigorously boiled over a period of about7 2 hours or until the methane has substantially or completelydisappeared. Atthe completion of the reaction, 1000 parts ofwater areadded and the product filtered off and Washed Well with water. Ifdesired, the 4.4-diaminodiphenylketone thus obtained may be purified'inany suitable manher, for example, bydis'solving it in dilutehydrochloric acid, filtering, and-then slowly adding to the filtrate adilute solution of caustic soda in an amount not quite sufficient tomake the solution alkaline. The precipitated ketone is filtered off andWashed wlth water.

The proportions given by Way of exemplification can be varied. A causticsoda concentration less than fifty percent apparently has little effectother than on the yield; but-with higher concentrations, about sixtypercent Or more, the reaction does not go to completion and undersirabledecomposition products begin to form. The sulfur content also can bealtered, but. for best results the amount of sulfur should besubstantially sufficient to form the thioketone and to con vert all thesodium hydroxide into a thiosul fate. Upon the addition of sulfur to thecaustic 'soda at temperatures substantially below 120 (1., it is foundthat the sulfur is largely present as free sulfur when the methanederivative is added; this uncombined condition of the sulfur, prior tothe addition .of the methane derivative, is further evidenced by thenecessity of holding the mixture at about 120 C. for an extended periodbefore raising to boiling, a reaction between the caustic soda andsulfur a arently occuring at. this temperature. lie temperature at whichthe mixture boils varies with the caustic soda concentration; with afifty percent solution, the temperature is about 127128 C., but withmore dilute caustic soda solutions the boiling point is correspondinglylower. Agitation throughout the whole process is of importance insecuring a uniform reaction and avoiding overheating; and vigorousboiling while refluxing is going on is desirable for removing thecaptans and other diami'nodiarylketone'body which comprises subjectingwith agitation a 4.4-diam1nodiarylmethane body to the action of a fiftypercent solution of caustic alkali containing sulfur at a refluxintemperature.

4. -'A process for t e production ofa 4.4' I

diaminodiphenylketone body which comprises" subject1ng a v1.4-diaminodiphenylmethane body to the action of caustic alkali containingsulfur with vigorous boiling .and vigorous agitation. I 5; A process forthe productionbf a 4.4-

diaminodiphenylmethane body which. comprises subjecting a4.4-diaminodiphenylmethane body to .theaction of caustic alkalicontaining sufficient sulfur to form a thioketone and to convert thecaustic alkali to a thiosulfate.

6. A process for the productionof 4.4"-

' diaminodiphenylthioketone body which comprises ad temperaturesubstantially less than 120 C.,

admixing an N-substituted etAJ-diaminodiphenylmethane, maintaining saidmixture for aperiod of time at a temperature approximating 120 0., andthereupon subecting the mixture to a vigorous refluxing temperature. p I7. A process for the production of 4.4tetramethyldiaminodiphenylthioketone which comprises heatingtetramethyldiaminodiphenylmethanewith caustic alkali containing sulfur.r Y

8. A process for the production of 4.4tetramethyldiaminodiphenylthioketone which comprises boiling withagitation under a reflux a mixture of approximately ten parts of4.4'-tetramethyldiaminodipheny]- methane and fifteen parts of a fiftypercent caustic soda solution containing approximately sixteen parts ofsulfur.

- In testimony whereof I-aflix mysignatur FREDERICK KRANZ.

ng sulfur'to caustic soda at a

